Constant Power Generation Using Modified MPPT P&O to Overcome Overvoltage on Solar Power Plants

Indonesia is a tropical country that has the privilege of gaining sunshine year-round so that the utilization of solar energy as a solar power plant can be a potential power plant to be developed. One of the problems in the solar power plant system is the power instability generated by the solar panels because it relies heavily on irradiance and relatively low energy conversion efficiency. To solve this problem, the Maximum control of Power Point Tracking (MPPT) is required by the Perturb and Observe (P&O) methods. This P&O MPPT control makes solar PV operate at the MPP point so that the solar PV output power is maximized. However, the MPPT P&O control that works at the MPP point makes the output voltage to the load is also maximum that causes overvoltage. This paper, therefore, discusses the modification of the MPPT Perturb and Observe (P&O) algorithm for Constant Power Generation (CPG) that combines MPPT P&O with the power control settings to the maximum limit of solar PV. This method can set up 2 operating conditions of the solar PV namely MPPT mode and CPG mode. The MPPT mode works when the solar PV output power is smaller than the reference power to maximize solar PV output power. However when the solar PV output power is more than or equal to the reference power then the CPG mode works to limit the solar panel's output power. Based on the simulated results of this MPPT-CPG control shows the load output voltage response can be kept constant 48 V with less than 5% error that has been verified using a variety of irradiance and reference power.